Future Personal Air Transportation System
Prof. - Dr. J. Rohács
Department of Aircraft and Ships
Budapest University of Technology and Economics
Abstract
This paper is the shorted version of lecture presented at the Workshop organized by European Aeronautics Science Network and titled The Role and the Chances of Europe’s Universities in the Community Thematic Priority ‘Aeronautics and Space’ of the EU Framework Programme. The goals of this paper are the introduction of the activity and research fields of the Department of Aircraft and Ships working at the Budapest University of Technology and Economics and calling up the attention for special fields of possible international cooperation in development of the future personal air transportation system,.
Introduction
The 57 years old Department of Aircraft and Ships has a very wide field of activity including the all field of aeronautical sciences and air transportation engineering, because it is
the only one university Department working in field of civil aviation in Hungary.
At Budapest, the first
university lectures dealing
with theory of flight were delivered by professor Donáth
Bánki in academic year 1910 /
11 at the Technical University
[1]. His famous student and
assistant professor was Theodore von Karman (Kármán
Tódor) (Fig.1.). Since that, the
Budapest University of Technology
and
Economics
(BUTE) is the leader scientific center of aeronautical
sciences.
Fig. 1. First lecturer of aeronautics in Hungary professor
Bánki and his famous student Teodor von Karman
In period of world
wares, Hungary had a strong
and excellent level of aeronautical industry. However, after 1956 everything was destroyed.
The profiles of the Departments dealing with aeronautics were changed. Only department of
Aircraft and Ships kept and could reestablish his activity in aeronautics.
1
During the last decade, the Hungarian aeronautics has completely changed. The Lockheed together the Hungarian Airlines open a new aircraft maintenance company Aeroplex of
Central Europe, Lufthansa started business in aircraft maintenance, too, with organization the
Lufthansa Technik Budapest, the General Electric established the engine spar repair factory.
A lot of new small private companies started their business in field of production of the small,
light airplanes, air transportation, and aircraft repair.
There is a big change in scientific activity, too. During last decade five times more
scientific thesises were completed and successfully defended then in period 1960 – 1990.
The staff of the Department of Aircraft and Ships at the BUTE has a good cooperation
with many European universities, institutions and industry. There were initiated some interesting international level projects like unconventional flight analysis [2, 3] and development of
the personal air transportation system (PATS) [4].
Generally, the project PATS is based on the radically new ideas and it can become a
nice example of the future cooperation on the European level in many fields of interest.
In this paper, after introducing the Department of Aircraft and Ships, the project PATS
will be outlined.
1. Department of Aircraft and Ships
The BUTE is more then 200 years old technical university [5]. It has eight different
faculties. The Faculty of Transportation Engineering was organized in 1951. The current organization of the Faculty was developed in 1970, and the Faculty of Transportation Engineering now offers degree programs with concentrations in transportation and mechanical engineering.
The transportation engineering program [6] provides the essential scientific foundations and the most up-to-date technical knowledge available so that engineers who graduate
from this faculty can go on to design road, railway, waterway, air, industrial and trade transportation systems. Graduates of this faculty will also be able to develop and monitor these
systems reliably and economically, using the latest in management theory and informatics.
The mechanical engineering concentration aims to give students a thorough scientific
foundation for development and design work, production control, and the operation and
maintenance of mobile machines at an advanced level. Further specializations are offered in
vehicle engineering and in mechanization engineering [1, 6].
The students of the Faculty can specialize in many different directions including the
air transportation engineering and aeronautical sciences.
The Faculty of Transportation Engineering offers a four year B.Sc. program, a two
year M.Sc. program, in English Courses, and a 5 year M.Sc. course in Hungarian education
and postgraduate courses that cover certain subjects thoroughly and allow for the pursuit of a
Ph.D. degree.
The faculty has 10 Departments. One of them is the Department of Aircraft and Ships.
The Department is giving lectures in basic subjects: thermodynamics, fluid mechanics;
thermal and fluid machines, and professional subjects aerodynamics, flight mechanics, airframe, aircraft design, airframe, aircraft systems, aircraft operation, gas turbines, design of gas
turbines, aircraft of civil aviation, airworthiness and requirements, innovation in aviation, as
well as theory of ships, ship dynamics, etc. for students of branches managed by Department.
2
We have a good cooperation with number of
universities. For example
practical course in flight
measurement is organized
with help of Department of
Flight Dynamics and Control
TU Munich (Fig. 2.).
Fig. 2. Students of the aeronautical branch preparing the
flight measurement with professor Wagner from
TU Munich at the Nyiregyhaza Airport
The staff of the Department delivers lecture fluid mechanics, thermodynamics for 300 – 350 students
pro semester. The number of
students choosing specialization aeronautical science and
air transportation is about 25
– 35 pro years.
Our Department has
permanent teaching staff 11, part – time lecturers - 4,
invited lectures (leader managers of Hungarian aeronautical and air transportation industry,
members of Hungarian and foreigner universities) – 22 – 28 (depending on the semesters), laboratory and administrative staff – 4 persons and Ph.D. students – around 15.
The staff deal with thermo and fluid machines, structural analysis, design, function,
control-energy-environmental load tests, operation, maintenance, repair, qualification of aircraft, gas turbines and ships; analysis of vehicle related aspects of air (Fig. 3.) and water
transport.
2. Scientific activity of the Department
The Department has a very wide field of interest, because it is only one University
Department in Hungary, that works in field of aeronautical sciences, civil aviation, shipbuilding and water transport. This fact can little bit confuse us. Generally, we may know much
more than other scientist, but it is difficult to reach high level in all of this direction. With accordance to this problem we have defined the following research fields [1], in which we have
more activity and several interesting results leaded to the contribution of the successfully defended scientific theses.
Thermal- and Fluid Micro-Machines: design, investigation and applying condition
analysis of thermal and fluid micro machines, development of human applying micro instruments. We have some results in development of the micro fluid mechanics [7, 8, 9].
Vehicle Thermal Processes: analysis of the thermal utilization process of the vehicles, thermal-accumulators and their application to helping of the engine starting processes,
investigation of the thermal processes of vehicle air condition systems [10, 11].
Gas Turbines and Combustion Engines: analysis and development of the thermal
and fluid mechanical processes in ground and aircraft gas turbines and combustion engines,
modeling the dynamic and energetic processes, design of the monitoring and diagnostic systems, design of the optimal operational processes.
3
We were taken part
in development of the new
digital data recording systems [12] and diagnostic
methods [13] applied to gas
turbine diagnostics. For this
purpose, we were developed
a special method [14] for
determining the compressor
map on the basis of compressor geometrical characteristics. The methods developed by us for mathematical modeling the gas
turbines made possible to
analysis of the special operational conditions [15].
Fig. 3. Low-power gas turbine test bench
A special small, law-power gas turbine test bench was (Fig. 3.) built by us for testing
the turbine characteristics, possible application of the mathematical models and use of modern
control theory [16].
Aeronautical Sciences: Aircraft aerodynamics and flight mechanics, design and development of aircraft and its systems, unconventional flight analysis, investigation and qualification of dynamical and energetic characteristics of aircraft and their effects on the environment.
The Department of Aircraft and Ships at the Budapest University of Technology and
Economics about ten years ago initiated a long period research project [2] with goals the
 real flight situation modeling [17],
 application of flight data to real flight situation and accident investigations [18],
 study the flights after loosing the control (before accident and crash) [19, 20],
 investigation of the aircraft motions at high angle of attack [2, 3, 21],
 application of the methods of statistical flight dynamics [2],
 examination of the effects of aerodynamic and structural non-linearities on aircraft
motion and aeroelasticity [22, 23],
 development of new control methods and systems [24].
For example, we have got some very interesting results of investigation of trust vectored fighter dynamics for poststall motion (Fig. 4.).
An another result of this project is the development of the theory of anomalies [25].
The experience in theoretical and practical investigation of the unconventional flight
situation had leaded up to the organization of the series of international conference on the given topics. The members of scientific committee of this conference series were initiated a new
project called personal air transportation system [4, 26].
We have investigated the systems of aircraft, too. For example we were identified the
real characteristics of the hydraulic actuators and made a series of simulations with identified
model of actuator included into the aircraft control system [27, 28].
4
5
Special Airplanes: Investigation of helicopters, hang-gliders, parachutes aerodynamics and analysis their flight mechanical properties.
We have investigated the problems associated with the motion of helicopter rotor
blades, wing tip wortex of small airplanes used in agricultural aviation, flight mechanics and
dynamics of hang gliders, etc. [29, 30, 31, 32]. So, we have a great experiments in design, investigation, certification of the small and ultralight aircraft.
Fig. 5. Infrared images of military helicopters flying at different distance from point of
measurment
At the same time we were dealing with the military aviation, too. We had worked with
amount others on the replacement of the Russian made opto-mechanical data recorders to solid state data recorders on the fighters MíG [33], evaluation of the fighter replacement [34], investigation of the aircraft accidents situations [35], and development of the method for qualification of spars reducing the infrared radiation of helicopters (Fig. 5.) [36].
Air Traffic Management: design and development of air traffic systems, analysis of
air traffic trends, technical and environmental characteristics, air traffic regulation.
The domestic air traffic
was closed after Second World
War in Hungary. After change
in political situation our air
traffic was in transition. Even,
this transition may not finished
up to our days. Our Department has worked a lot on the
reestablishment and development of the regional flight in
Hungary [37, 38].
We had some interesting studies on the environmental impact of civil aviation,
namely we have developed a
new method for determining
the aircraft emission scattering
at airport regions (Fig.6.) [39].
Fig. 6. Principal schema of method developed by Department for determining the aircraft emission
scattering at airport regions
6
Water Traffic Management: design, arrangement and development of the water traffic, ship design and development, investigation of the effects of ships and water transport on
the environment.
Shipbuilding and machines: design, arrangement and development of shipbuilding,
analysis of ship motions, modeling, investigation and qualification of the dynamical, energetic
properties of ships and ships machine-elements.
The department has a large
laboratory contains several laboratory test benches including the different computer controlled fluid and
thermo machines, gas turbine test
bench (Fig. 3.) water channel, small
wind channel (Fig. 7.) and fix based
flight simulator (Fig. 8.) built for education and scientific purposes. This
simulator can use for testing a new
aircraft control ideas, pilot workload
evaluation, or new cockpit instrument testing [40, 41].
Fig. 7. Water channel of the Department applied
for investigation of ships dynamics
The Department has a good
condition in informatics. We have software
for CFM/CFD, FEM,
investigation of the aircraft
aerodaynamics
and flight Mechanics
(Advanced
Aircraft
Analysis software), full
version of MATLAB,
software for displayed
instrumentation design
VAPS, FLSIM for developed flight simulator
control, etc.
The department
has a very wide international relationship and
successful cooperation
with most of HungariFig. 8. Flight simulator built by Department with help of De- ans companies and inpartment of Flight Dynamics and Control at the Mu- stitutions working in
nich University of Technology
field of aeronautical
sciences and air transportation system. There are some large projects like unconventional flight analysis or development of the personal air transportation system. These projects are supported by international cooperating partners, too.
7
The technology is available to establish the safety, economical and environment friendly Personal Air Transportation System (PATS).
1400
1200
1000
800
600
400
200
0
GDP
cargo traffic
passanger traffic
year
19
70
19
75
19
80
19
85
19
90
19
95
20
00
20
05
21
00
The needs in personal transportation are increasing very rapidly by exponential way (Fig. 9.). Even intelligent
highways and high speed railways are not
the final solutions of problems of personal
traveling. As sun as possible we have to
develop the personal air transportation
system [4].
increaing (100 % related to
year 1960)
3. New problems generated by PATS
Fig. 9. Effect of economical development on
the traffic needs
The NASA has initiated already
his similar project [42] called as small aircraft transportation system (SATS). The NASA program is focused on the new aircraft design, airports development and economical foundation of the project.
The initiators of our PATS projects [4], famous professors and leaders of European
universities, institutions and companies think that the personal aircraft has to be design for use
by common people. So, we need principally new aircraft, which could be piloted by everybody, without any special or extra knowledge and abilities. Such aircraft will be used very
widely. Therefore we have to develop radically new air traffic control system and new airport
set. It seems that the principle of organization and operational system of the personal air
transportation system must be much closed to the philosophy of the personal car operation
system.
The PATS project deals with the development of the general PATS system, included
the development of the new smart aircraft, new set of airports (Fig. 10.), new technology for
improving the flight safety, new pilot
cockpit instrumentation, new concept for
air traffic control, etc.
The establishment of PATS needs several
families of the personal aircraft. The market analysis shows that the 4 – 9 seats aircraft are required. They can be equipped
by the propellered engines. Of course, the
noise of the engines has to be reduced, because the personal aircraft will be operated
at airports closed to the city centers. If the
range of the aircraft would have greater
then 400 km-s, the use of jet engines
would be the right decision.
Fig. 10. Vision on the new small airport
Principally, for last 40 years, the
small aircraft applying the latest results of the sciences and technology have not developed.
So we need absolutely new designed aircraft. The main objectives of the small aircraft development are characterized by
 developed aerodynamics – even use of revolutionary concepts,
8



principally new designed engines – with reduced fuel consumptions, noise and air
pollution, (possible diesel engine and jet solutions),
excellent performance – for good and safety piloting,
excellent ride control – with application of active and adaptive control methods,
good technical life – with reduced fatigue damages, use of damage tolerance design philosophy, etc.
The possible boundary of the performances can be characterized by very serous conditions. For example, as it was defined by leadership of the NASA’s SATS project [6] the engines to be designed for small aircraft should have law weight, high reliability and radically
reduced primary cost and low operational cost. The initiated GAP (General Aviation Propulsion) Project resulted to new piston and turbofan engines. The intermittent combustion engine
is designed for a single engine, no more then 4 seats small airplanes having cruise speed maximum 200 knots. The images of a new Diesel engine designed [6] and its mean design features are given in Figure 5. This engine has fuel consumption of about 25 per cent less than
current engines
Such aircraft will build with use of latest result of sciences and technology, like
MEMS (Micro-Electro-Mechanical System,) technology, fault tolerant, reconfigurable control
systems, new control based on neural networks, etc.
The new aircraft will be piloted by common people. So, we have to develop safer aircraft for radically decreasing the flight risk, especially in case of their wide personal use by
common pilot would have not special flight training.
The philosophical approach to flight safety of personal air transportation system can
be characterized by
 application of automatic adjustment system for automatic setting up the best flying
configuration, condition (for example automatic adjustment of stabilizers or reference model of control system depending on the center of gravity measured during
taxiing),
 simplifying the control system, which can not more complicated then ordinary car
control (computer assisted control system with automatic limitations on critical regimes, integrated engine and aircraft control (Fig. 11, 12), connecting the roll and
yaw control into one channel),
Fig. 11. Integration of the engine and elevator controls
9





pilot assessment system (including automatic voice checklist, pilot load condition
estimation, gust effect elimination, automatic detection of pilot failures, overtaking on pilot decision in emergency situation with leading to stabilized horizontal
flight and switch on the distance control
system, e.g. control from ground for land
the aircraft in out of pilot control case,),
ride control system for increasing the passengers’ comfort (because the personal
aircraft will used at altitude 2 – 4 km region, which is a most turbulenced region
of air),
advanced cockpit instrumentation with developed advisory system for safe piloting
(Fig. 11),
specially equipped airport net (with use of
radically new systems even),
radically new air traffic control system or
better to say, development of the air traffic
rules for personal air transportation system.
Generally, it may the most interesting and revolutionary task is the simplifying the control system.
For example, with help of internal model principle Fig. 12. Comparison of the inteand feed-forward technique the engine and elevator
grated (IC) and conven(altitional (C. A/C) control
tude)
controls can be integrated into one system
(Fig. 8.). In simple case, when pilot is pushing on the gas, pushing the throttle to forward, only, the system automatically will
keep the airplane on the same flight direction
(in horizontal flight or in climb with constant
climb rate).
Summary
This paper was submitted to the special EASN workshop. The paper tries to introduce the Department of Aircraft and Ships
working at the Budapest University of Technology and Economics.
Fig. 13. Cockpit vision of NASA developers (upper image) and HUD with
3D guidance information (lower
picture) developed and investigated
at TU Munich
The goal of workshop is to develop
the collaboration between the participants.
Therefore this paper made short overview on
activity of Department. The shortly outlined
project PATS may be a most interesting field
of future cooperation.
10
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11
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